The Drunken Monkey: Why we love to drink

There is no doubt that humans have a complicated and persisting relationship with alcohol. Scientific forays into why we love the substance are certainly not new, but the more research that is conducted, the more complex intersections between social, behavioural, biological and psychological factors are revealed. Even a cursory glance at just one of these categories reveals mountains of research and diverse conclusions. Genetically based investigations in particular have resulted in a variety of diverting hypotheses that provide intriguing explanations for our relationship with alcohol.

Several studies have shown that genetic variation gives a taste (or otherwise) for spirits. Simply put, one particular investigation states that a particular type of gene (the TAS2R38 profile) determines how sensitive people are to bitterness, meaning that people whose taste buds are dulled to bitterness are more likely to consume larger amounts of alcohol than those who are not. However, many scientists are more interested in where this affinity comes from in the first place. Ethyl alcohol, or ethanol, has been a staple in the human diet for more than just centuries. The human love affair with fermented beverages goes back as far as 7000 BC, and perhaps even further according to some archaeologists.
Our understanding of this relationship has been hugely advanced in the last ten years by research into the evolutionary foundation for attraction to ethanol, including a concept called the Drunken Monkey Hypothesis. The Drunken Monkey Hypothesis, however silly it may sound, is the result of an observation made by scientists in 2004 of a howler monkey eating the monkey equivalent of ten standard drinks worth of fruit in twenty minutes (fruit contains ethanol in amounts that have no effect on humans, but entertaining ones on howler monkeys).

The hypothesis essentially states that human attraction to ethanol has a genetic basis and attempts to partially explain why we have such an enduring relationship with the substance. The observers, Dustin Stephens and Robert Dudley, noticed that the monkey behaved like a “drunk teenager” and concluded that, in monkey terms, he was. Stephens and Dudley assert that a marked attraction to the smell and taste of alcohol provided a selective advantage for primates because it allowed them to locate fruit at its ripest. Eventually, humans learned to distil spirits in order to condense the alcoholic content of fermented fruit and grain, and what was initially an advantageous attraction became a potentially dangerous one. This unfortunate reversal is often attributed to a disparity between prehistoric and contemporary environments as well as the development of the ability to distil alcohol in high concentrations. Stephens and Dudley admit that the hypothesis by no means provides a definitive or all-inclusive answer, and indeed raises many more questions.

Combining evolutionary theories such as this one with more individualised behavioural and genetic research, gives scientists a far more nuanced understanding of why alcohol abuse is so prevalent. And ultimately, what all this research is important for is developing individually focused treatment and prevention techniques for abuse and addiction of alcohol.